Arthur greiner



(No Model.)

A. GREINER.

PROCESS OF MELTING METAL.

No. 445,056. Patented Jan. 20, 1891.

WITNESSES: INVENTOR NlTED STATES PATENT OFFICE.

ARTHUR GREINER, OF CHISNOVODA, AUSTRIA-HUNGARY.

PROCESS OF MELTING METAL.

SPECIFICATION forming part of Letters Patent No. 445,056, dated January 20, 1891.

Application filed October 15,1885- Serial No, 180,029. (No model.) Patented in Germany March 28. 1885, No. 33,212; in

France May 20, 1885.110, 169,043; in Belgium May 20, 1885, No. 68,950, and in England June 6,1885,N0.6,939.

To all whom, it may concern.-

Be it known that I, ARTHUR GREINER, a subject of the King of Hungary, residing at Ghisnovoda, in said kingdom, have invented certain new and useful Improvements in Processes of Melting Metal, (for which I have received Letters Patent in Germany, No. 33,212, dated March 28, 1885; in France, No. 169,043, dated May 20, 1885; in Belgium, No. 68,950, dated May 20, 1885, and in Great Britain, No. 6,939, dated June 6,1885;) and I do hereby declare that the following is a full, clear, and exact description of the invention, which will enable others skilled in the art to which it appertains to use the same.

My invention relates to improvements in the process of melting in cupola furnaces which have tuyeres entering the same above the zone of fusion, for the purpose of supplying air to consume carbonic oxide.

The object of my invention is to effect a greater economy in the consumption of fuel required for melting metal in cupola-furnaces, and to increase the efficiency of the furnace; and it consists in a novel process, hereinafter fully explained, which is illustrated by the accompanying drawings, in which Figure 1 represents a sectional elevation of a cupola-furnacc to which is attached a suitable arrangement of tuyeres. Fig. 2 is a horizontal section of Fi 1 taken on the line A B.

The dotted line. C D represents the upper boundary-line of the fusion-zone for the purpose of illustration; but, in fact, this line does not always occupy a fixed height above the lower tnyeres c, as its position depends on the character of the fuel, the construction and capacity of the furnace, and the rapidity of melting, which at times vary in the same onpola.

Similarletters refer to similar parts throughout the several views.

The upper or smaller tuyeres are designated by the letter (Z, the lower tuyeres by the letter 0, and the blast-box for the lower tuyeres by the letter Z).

In the ordinary process of melting in cupo las air for combustion is introduced through tuyeres in one or more rows 0, at a distance above the bottom var ing according to the intended capacity of the furnace. This air combines with the fuel in the fusion-zone and burns the coke in front of the tuyeres to car bonic-acid gas, a combination indicating perfect combustion. As this gas ascends through the incandescent fuel above, it takes on an equivalent of carbon therefrom and it is nearly all reduced to carbonic oxide, one equivalent of carbonic acid taking on or absorbin g one equivalent of carbon forming two equivalents of carbonic oxide; and as there is always incandescent fuel above the melting-zone in cupola-furnaces when in operation, carbonic oxide is thus being formed continuously and escapes through the throat of the cupola, causing thereby the loss of the equivalent of carbon so taken on or absorbed unless provision is made to consume the carbonic oxide within the cupola. To avoid this loss of carbon additional tuyeres have been placed at a short distance above the lower tuyercs and melting-zone, to introduce air to consume the carbonic oxide 5 but such device does not have the effectintended, because the descending materials at that place in the eupola have a very high temperature. Consequently the air so introduced also ignites the solid fuel and the zone or layer of fuel immediately above becomes incandescent, giving off carbon to the ascending gases, thereby forming carbonic oxide, which escapes at a loss, as before.

In all cupola-furnaces there is a space or area in which the descending materials are not hot enough to become incandescent by air introduced according to my process, and also in which the ascending gases of carbonic oxide are still warm enough to ignite on contact with the air so introduced. This space I denominate the neutral zone. It begins practically above the lower tuyeres c at a distance therefrom of ten times the diameter f the pieces of coke or fuel used, as I have discovered by actual experiment. It is not new to introduce air into the space occupied by this neutral zone; but prior to my invention its location and the facts of the variation of its location during the process of melting was not definitely known; but the introduction of air thereto by others was to the space above the incandescent fuel generally without any recognition of the neutral zone as herein described, and such introduction has been either at the same pressure as at the lower tuyeres or in such manner that no certain pressure could be had or maintained, and also regard-.

less of both the quantity of the air introduced and of its uniform distribution and of any regulation. These facts demonstrate that such persons had not conceived the true relations and conditions required for complete combustion of carbonic oxide. If too little air be introduced, only a part of the carbonicoxide gases will be consumed. If too much air be applied, an increased formation of carbonic oxide may take place, causing a loss instead of a saving of fuel. TlllS occurs when too many upper tuyeres are used, or they are placed too near together, or are made too large, or when too great a pressure of air is used, the result being that the ascending gases are burned in too small an area of the cupola, raising the temperature so high that the fuel becomes incandescent and frequently ignites, producing loss of carbon in like manner, as before described. It is therefore not sufficient to simply introduce air to the neutral zone in any of. the ways heretofore adopted.

I have discovered that the combustion of the carbonic oxide to be complete and fully utilize the fuel within the cupola must take .place within this neutral zone; also that the combustion of the carbonic-oxide gases must be regulated so as not to heat the solid fuel to incandescence in any part of this neutral zone; also that the combustion of the carbonic-oxide gases must take place in an area of the cupola as large as possible; that to aid in extending this area and to prevent the temperature rising too high in any part of this neutral zone the air must be introduced in small currents uniformly distributed throughout the neutral zone through many small tuyeres, preferably not exceeding one inch in diameter. I have also discovered that the pressure of the air introduced to this neutral zone must vary at different times according to the condition of the combustion within and must always be less than that of the lower tuyeres, preferably in the proportion of two below to one above; that different pressures andquantities of air are required at different times and at different places in this neutral zone during the process of melting to prevent incandesence of the solid fuel and to furnish the exactquantities of air required to completely burn the gases, and that this depends upon and varies with the rapidity of the melting and the character of the fuel. To enable me to meetthese conditions for the complete combustion of the carbonic oxide, I provide the following mechanismto carry out my process, and which may be attached to any cnpola-furnace. I place a number of small tuyeres, preferably not exceeding one inch in diameter, one above the other, either in rows in an ascending series or in a-l eligal curve (not shown) in the upper part of the cupola. The first tuyeres or row of tuyeres d is placed at a height above the melting-zone where the fuel has not yet reached a state of incandescence. This height depends upon the size, construction, and capacity of the furnace, and must be ascertained in each particular cupola by observation, so that I can begin the consumption of carbonic oxide with its first appearance in the neutral zone. I distribute the other small tuyeres d, numbering from eight to thirty-six, according to the size and capacity of the cupola, evenly one row above the other, or in an ascending helical curve (not shown) from this first row of tuyeres to or nearly to the upper line of the materials in the cupola when fully charged. 1 provide each of these small tuyeres with peep-sights 1', and each or every'frow with valves g, and connect them with the supply-pipe e, which is also provided with a valve f, andis connected with the main pipe at, leading from a blowe here the tuyeres are placed in rows, a bustle-pipe h is'used for each row and one valve 9 is used for each bustle-pipe, which is connected to the supply-pipe 6.

My process consists in applying air to the neutral zone through these smalltuyeres during the process of meltingin accordance with the above-described conditions for the complete combustion of the carbonic oxide. The exact condition of combustion of gases in the neutral zone is ascertained by the temperature of the small tuyeres and from the appearance of the interior as seen through the peep-sights. The pressure is regulated by the valves, so that it shall always be less than at the lower tuyeres, preferably in the proportions above named. Should the solidfuel become incandescent in front of any of the tuyeres, the supply and pressure of the air is reduced. If this does not prevent incandescence that tuyere is shut off. Should any of the small tuyeres become hot, it is evidence that the pressure of the air is not sufficient to overcome the pressure of the'hot gases in the c-upola, and the pressure should then be increased. It will thus be seen that the introduction of the air can in this manner be regulated so as to meet all the conditions of perfect combustion of carbonic oxide above set forth. The combustible gases are thus burned without heating the solid fuel to incandescence, and the heat thus developed preheats the surrounding materials, so that they reach the fusion-zone at a higher tempera ture. The solid fuel reaches the melting-zone at a temperature nearer its point of ignition and the metal nearer its melting-point. The fuel will therefore require less additional heat to ignite in the melting-zone and the metal also less heat and time to melt. There is thus caused a more complete utilization of the fuel and less fuel is required to effect the melting, and the efficiency of the furnace is increased by the more rapid melting in the melting-zone and by theadditional room in the furnace for the metal that previously was occupied by the extra amount of fuel not now required, and the melted metal is not subjected to so much oxidizing carbonic-acid gas, because less is developed in the meltingzone, and thereby the loss through Waste of iron is reduced.

Having thus described my process, I do not claim, broadly, the process of consuming carbonic oxide in cupolas by introducing air above the incandescent fuel; but I am not aware that prior to my invention air so introduced has been confined to the neutral zone described or admitted in the manner above described; but

What I do claim, and desire to secure by Letters Patent, is-

The within-described process of melting iron with coke fuel in cupolas, which consists in applying air in a number of smallourrents in an ascending series throughout and confined to the neutral zone in cupola-furnaces to the combustible gases therein during the process of melting at a pressure less than that at the lower tuyeres, preferably in the proportion of two below to one above, and regulating the same during the process, so that the pressure and quantity of the air applied to the different parts of the neutral zone shall be adapted to consume the carbonic oxide therein without heating the solid fuel toincandescence, substantially as described.

In testimony that I claim the foregoing I have hereunto set my hand this 25th day of April, 1885.

ARTHUR GREINER.

\Vitnesses:

A. M. ROEHENDORFER, HENRY STERNE. 

